It is common practice to include in cookies particles of flavoring materials which remain in the baked cookie as discrete, heterogeneous particles. Such flavor particles may include chocolate chips, butter-scotch chips, caramel chips, raisins, nuts, cherries, and various types of berries such as blueberries and raspberries. The presence of such flavor particles in the cookie enhances the flavor and consumer acceptability of the cookies.
Unfortunately, the presence of the flavor particles as heterogeneous inclusions forming a phase distinct from the substantially homogeneous dough portion of the cookie may result in one or both of two undesirable effects in the cookie. The first of these effects is a so-called "bloom", which appears as a whitish deposit, either in the form of discrete particles or a continuous layer, covering parts of the surfaces of the flavor particles. The second undesirable effect is the so-called "halo" effect which consists of a marked lightening in color in the parts of the cookie adjacent the surfaces of the flavor particles or on the surface of the cookie in parts of the cookie where the flavor particles are covered only by a thin crust. Although neither the bloom nor the halo effect poses any health risk (the cookies are still safe to eat), both do tend to make the cookies esthetically unappealing. Bloom and halo effects are especially visible in chocolate chip cookies. The dark color of the chocolate chips makes any bloom thereon highly visible, thus giving rise to the so-called "blonde chocolate chip" phenomenon well-known to those skilled in the art. Blonde chocolate chips are mainly experienced in cookies having high moisture contents and relatively low levels of fat or shortening. The dark color of the chocolate chips also makes any lightening of the cookie caused by the halo effect highly visible. Bloom may also cause a serious problem in high moisture raisin cookies and in English muffins containing raisins; in these cases, not only does the dark color of the raisins make any bloom highly visible, but the high moisture content of the raisins appears to facilitate the development of bloom.
It is believed that fat bloom results from the formation of crystals of fat on the surface of the flavor particles, and that halo effects are caused by changes in the form of the sugar crystals on the dough portion of the cookie. Also, it appears that cookies of high moisture content are more susceptible to both fat bloom and halo effects than cookies with lower moisture contents. Fat bloom occurs in chocolate or chocolate products which have been subjected to improper tempering or too sudden cooling. Fat bloom also may occur in chocolate chip cookies formulated with a high proportion of liquid shortening (oil). It is believed that during storage of such cookies, the oil migrates to the surface of the cookies and comes into contact with the chocolate chips. The oil in contact with the chocolate chips exerts a eutectic effect on the cocoa butter in the chips, causing them to soften. The cocoa butter then undergoes polymorphic changes during storage leading to the development of fat bloom on the chocolate chips on the surface of the cookies.
Halo effects may develop when dew or moisture condensation occurs on the cookies during the cooling and packaging stages which follow baking. Sugar crystals in the vicinity of the condensed moisture are dissolved, and when the surface moisture evaporates minute sugar crystals become visible as rings which surround flavor particles such as chocolate chips. It is believed that water collects on the cookie surface around the flavor particles by condensing on the raised portion and flow down to the area surrounding the flavor particle. It may also be caused by differences in heat capacities and cooling rates between the flavor particles and the surrounding baked dough or by flow of moisture from within the cookie around the flavor particle.
Attempts to eliminate these effects are greatly handicapped by the unpredictability of the effects. Even though the ingredients and the proportions of ingredients in successive batches of the same cookies are kept as constant as possible in large-scale cookie production plants, the unavoidable slight variations in formulation, processing and storage conditions may cause bloom and halo effects to occur in a few batches of cookies from a specific plant, while the remaining, supposedly identical, batches from the same plant are free of these defects. Moreover, since bloom and halo effects may only become visible after the cookies have been packed, it is difficult to prevent cookies suffering from these effects reaching the consumer.
There is thus a need for a process for making cookies containing flavor particles less susceptible to bloom and halo effects, and this invention provides such a process.
This invention provides a process and a dough composition for producing multi-textured cookies which retain a firm texture in their outer layer at high water contents and which are bloom and halo resistant during storage.